In recent years display devices which use a mechanical shutter based on MEMS (Micro Electro Mechanical Systems) technology are gathering attention. A display device which uses a MEMS shutter (referred to as [MEMS display device] below) controls the amount of light which passes through a shutter by rapidly opening and closing a MEMS shutter arranged on each pixel using a TFT to adjust the brightness of the pixels (For example, refer to Patent Document 1 [Japanese Laid Open Patent 2008-197668]). A time-ratio gray scale method is adopted in the MEMS display device whereby an image is displayed by switching in sequence red, green and blue light from an LED backlight. The MEMS display device does not require a polarization film or color filter which are used in liquid crystal display devices and is characterized by having around ten times the usage efficiency of backlight light and half or less the power consumption compared to liquid crystal display devices and also has excellent color reproducibility.
In a MEMS display device a TFT which comprises a switching element for driving a MEMS shutter and a gate driver or data driver for driving the switching element is formed on a substrate. A terminal for supplying an external signal to the TFT is simultaneously formed on the substrate. Usually, in the MEMS display device a passivation film which covers the TFT and terminal is formed on the TFT substrate formed with the TFT and terminal, and a MEMS shutter is formed on the passivation film. Following this, an opposing substrate is bonded to the TFT substrate formed with the MEMS shutter. Since it is necessary to supply an external signal to the terminal formed on the TFT substrate, the TFT substrate and opposing substrate and bonded together so that the opposing substrate does not cover the upper part of the terminal.
Since is necessary to supply an external signal to the terminal formed on the TFT substrate it is necessary to remove the passivation film on the terminal. Usually, in a TFT or semiconductor process the passivation film on the terminal is removed by combining a photolithography process and etching process. On the other hand, in the case of a MEMS display device the working parts of a MEMS shutter are in a floating state and thus it is often difficult to apply a photolithography process (resist coating etc) after forming the MEMS shutter.
In addition, there is a method for removing the passivation film on the terminal by a dry etching process after bonding the TFT substrate and opposing substrate and cutting them into individual MEMS display devices. However, in the removal method of the passivation film there is a problem in which the manufacturing throughput of a MEMS display device drops significantly and specialized devices are required.
In addition, while there is a method for removing the passivation film by irradiating a laser onto the terminal upper part the manufacturing throughput of a MEMS display device drops significantly.
Thus, the present invention was realized in an attempt to solve the problems described above by providing a display device and manufacturing method of the display device in which specialized devices are not required and whereby a passivation film is removed from a terminal without decreasing manufacturing throughput.